Engraving machine



Feb. 8, 1927,

L. K. BRAREN BNGRAVING MACHINE Filed Dec. 14. 1925 3 Sheets-Sheet 2 Inueh, Z07 jorergllfinradfirarem Feb. 8, 1927.

L. K. BRAREN ENGRAVING MACHINE Filed Dec. 14, 1-925 3 Sheets-Sheet 5 Patented Feb. 8, 1927.

"UNITED STATES PATENT poetics- LORENZ KON'RAD BRAREN, 0F MUNICH, GERMANY, ASSIGNOR TO THE FIRM FRIED- ;RICH DEOKEL, 'PBAZISIONSMECHANIK "(IND MASCHINF NBAU, OF MUNICH, BA-

VARIA, GERMANY..

' mvenavrne menmn.

' Application filed December 14, 1925, Serial No. 75,453, and in Germany December 8, 1924.

This invention relates to improvements in engraving machines and has for its ob]ect the production of various parts of different shapes and sizes especially stamps and dies in steel or any other hard material. For this purpose a method is provided whlch ronsists in producing the desired shape from a model of the same size on a reducing engraving machine.

There are furthermore provided means for producing a counterpart die for embossing material of even thickness with due allowance for the distortions due .to the material between the die and counterpart die for use therewith.

Engraving machines are known, which cut equivalent shapes of the same size as the model. But when cutting stamps or dies in steel or in any other hard material in a proportion of one to one, thecutting pressure is so great that it becomes difficult to handle the machine and to prevent deflections in the pantographic system especially with'the model located on one side and the work on the opposite side of the supporting axis of the pantograph or with model and work along side of each other parallel to the supporting axis. A counterpart to a iven die or vice versa with due allowance or material of even thickness in between cannot be produced very well on such a machine.

According to the piesent invention a simple. reducing machine, for instance a machine as has been shown and described inmy copending application filed Dec. 4, 1923, Serial No. 678,485, is used and the shape, of which a reproduction of the same size is wanted is fastened to the work table while a block of hard wood is held to the co ying table for holding the model. Instead of wood any other material may be used whlch can be worked readily yet is of suflicient hardness to serve as a model for a single copy. The copying stylus and the bearing for the rotating cutting tool are designed to be exchanged readily thus facilitating the production of anenlarged model. As

a rule it is not advantageous to enlarge or' even to work in ratioof one to one, but wood, plaster of Paris or a similar material may readily be handled in this manner. The shape desired is now produced from this enlarged model with the same setting of the pantographic system as was previously used for enlarging, but with .cutter bearing and .above and in line with the cutter bearing which is held elastically against the model.

Thus a movement sidewa s of the pantograph causes the cutter caring to move vertically according to the contour ofthe model. While this method of producing a counterpart of a given shape has been known, it was not possible to work in hard material or to a great depth. Therefore, in

order to divide the total cut into a number of steps the support for the model is mounted on the carrier for the pantograph system which pivots on a vertical axis. An adjustable stop limits the depth 'of the cut and thus, by varying the setting of the stop, out

after cut may be taken. In order to make proper allowance for the material between a die and a counterpart die, cutter and guiding point are fashioned with ball shaped ends of difi'erent radii.

When taking heavy cuts in hard material especially when roughing out a tool in tough steel it is difficult to guide the pantograph by hand as the cutter has to be supported against'movement in any direction of space.

In order to overcome this difliculty means are provided for guiding the tool in a plane so that the cutting pressure need only be supported by hand in one direction which.

facilitates very much the handling of the machine. For this purpose the cutter hearing is supported by a guide arranged adju'stably on a slide above the bearing. For finishing the part the guiding arrangement of course is removed- In order that this my invention may be more readily understood reference is made to the accompanying sheets of drawings which show how the invention may be carrled intopractical effect.

.Fig. 1 is a view of the engraving machinef Fig. 2 shows the arrangement of the cutter bearing on larger scale, partially in section.

Fig. 3 is a section through the copying stylus on the same scale as Figure 2,

Fig. 4 shows diagrammatically how a counterpart die isproduced with allowance for an even thickness of material between.

Figure 4. p

Fig. 6 shows the arrangement for guiding the cutter bearing in one plane.

Fig. 7 is a side view of the arrangement shown in Figure 6 partly in section.

Figure 8 is a top plan of the machine shown in Figure 1;

Figure 9 is a view illustrating the development of an annular groove in the bracket of the spindle holder for receiving pins upon the-holder as shown in Figure 2; and

Figure 10 is a sectional plan taken on line 1()10 of Figure 3.

The parallelogram of the pantographic system consists of four arms 1, 2, 3 and 4 of which 1 and 2 are hollow castings in which are mounted supporting screws 5 with conical points. The arms 3 and 4 are tubes on which slides 6 and 7 are mounted. The slides are provided with depressions for the screws 5; they can be fastened in different positions by screws 8. A bracket 9 for the cutter bearing 41 is fastened by bolts 10 to the arm 2 and may be adjusted on the arm according to the ratio desired. The cutter spindle 11 is rotated by a sheave 12. The copying stylus 13 is arranged in a bracket 15 fastened to the arm 4. A handle 16 is provided for guiding the vpantograph esturnably around the same axis in a similar manner by intermediate pins arranged in the arm 1. To compensate the one sided weight of the pantograph system, the arms 1 and 3 project from the pins 17 and 18 towards the rear and are provided with rods on which adjustable counterweights 23 are arranged. The carrier 19 is located turnably on conical points 24and 25 at right angles to the pins 17 and 18 in a bracket 26 which latter is fastened to the frame 27 of the machine. A work table 28 is arranged on a guide of the frame 27 and may be adjusted by handwheels and screws in three directions. The copying table 30 is located turnably and adjustably up and down in a bracket 31. An arm 32 is pivoted on a bolt 33 fastened in the carrier 19 and is fashioned with a slot through which a rod 34 passes. The rod is fastened in the bracket 26. An adjusting screw 35 serves as a stop abutting against the rod34 for fixing the depth to which the cutter may enter into the material.

spindle 11 is mounted in a bearing 41 on which there is slidingly located a sleeve 42 provided with two pins 43. In the bracket 9 there is provided a circular recess 44 for these pins 43 which recess is connected downfor fastening any desired part.

rerasia tends to hold the sleeve 42 into depressions 44" of the recess 44 and holds also the bearing 41 in contact with the sleeve 46 for controlling the axial adjustment which operates up and down by turning a knurled disc 47 and therewith a threaded connection 70. A

holder 48 for the copying stylus 13 is con structed very similar to the bearing 41 of the cutter spindle and carries a bushing 49 with two pins 50 which are held by a spring 51 in a circular recess 52 of the end bracket 15 having downwardly extending grooves 52 arranged at right angles to the normal position of the pins to permit withdrawal of the bushing49. The holder 48 is fashioned with a; tapered lower end, which is threaded and formed as a split sleeve having three slots to permit the tightening of a nut 53 to clamp the copying stylus. Exchangeable guiding pins 54 corresponding to the contour of the revolving cutters are inserted in a taper seat of the copying stylus 13.

By arranging the cutter bearing and the holder for the copying stylus with an identical bayonet fastening, it is possible to exchange these two by only a few simple movements. In order to surely prevent any axial displacementof cutter and copying stylus after adjustment, the bracket 9 and the end bracket 15 are both slotted and provided with clamping screws 55 and 56.

For fastening a model abovethe cutter spindle there is provided a slide or support 57 on the carrier 19 having gibs, not shown, which are adjustable in guide ways of the carrier and may be clamped by an eccentric bolt 58 constructed in a well known manner. The support 57 carries on the front end a cylindrical post 59 on which is adjustably mounted a table 60' supported by a sleeve clamped upon the post by an eccentric bolt 60. This table is provided with '5' slots A counterweight 61 is arranged adjustably on the rear end of the support 57. For contacting with the model there is provided an exchangeable guiding point 62 fitting in a taper seat not shown of the sleeve 76 for axial adjustment of the cutter spindle. exact allowance for a given thickness of material, is made by using a cutter and a guiding point 62 with ball shaped ends and by choosing a radius for the guiding point equal to the radius of the cutter plus the thickness of the material. When using a pointed cutter the radius of the guiding point, of course, should equal the thickness of the material to be worked. This statement may readily be verified by studying the diagrammatic Figures 4 and 5.

With the model fastened to a table which follows the up and down movements of the pantograph system around the horizontal axis it is possible to limit the dc th of cut,

which depth may be varied by ad usting the screw 35.

For heavy cuts, as already explained, it is of advantage to limit the moveability ofv the cutter to a single plane. In the figures 6 and 7 there is shown an arrangement for .this purpose, which is located on the table 60 above the spindle bearing, but which may be arranged on the model table 30, where it must be fastened when cutting a counterpartdie as described previously. Instead of the guiding pin 62 there is fastened in the taper seat of the cutter bearing a cylindrical arranged to travel.

which will be ,spring 45.

pin 62 which may move'axially in a bore of a sliding shoe 63. This shoe of cylindrical shape is held between two guides 64 and 65 mounted on a small slidefiti, the guides having grooves 64 in which the sleeve is The slide 66 is moved back and forth through cooperation therewith of a well known type of feed screw 67 having a handle 67, movement of the slide serving to vary the position of the cutter.

In' this manner the work on a given body may be divided into a number of parallel planes the cutting pressure being taken up by the spring 45 surrounding the cutter spindle.

The knurled disc47 is connected by a set screw 71 to a sleeve 72 which is provided with a shoulder 73. The sleeve 72 is held in a bushing 74 pressed into the bore of the bracket 9 and secured by a set screw 75. The bushing 74 is provided with an internal step corresponding to the shoulder 73 which holds the disc 47 and the sleeve 72 against axial movement. An adjusting screw 76 partakes of any turning movement of the disc 47 and the sleeve 72 due to a. in 77 connected to the screw and a keyway 2 cut in the sleeve,

but is free to move axially. The screw is threaded in a nut on the sleeve 46 which is held radially in the bore of the bracket 9. A pin 46* is secured to the nut 7 O and slides with the head in a slot 78 of the bracket thus holding the nut against'turning and limiting its axial movement as well as the movement of the cutter spindle in the. bracket 9. In order to prevent accidental disengagement of the screw and nut there is provided a screw 79 in the lower end or the adjusting screw 76 acting as a stop for the nut 70. In the upper endof the adjusting screw a tapered seat is provided for the guiding point 62.

The cutter spindle therefore may be moved axially by turning the disc 47 and also by applying pressure to the 'uidin point. 62 yieldably resiste d by the It will be understood that the invention herein described is capable of modification cutting point by a difference equalin and a guide for the cutting means free to slide upon the shoe.

2. In an engraving machine, a frame, a carrier mounted upon said frame to freely swing in a vertical plane, a pantograph pivotally mounted upon the carrier to swing thereon, cutting means secured to said pan-- tograph, and a model holder mounted upon the carrier and adapted to swing therewith in said plane during the cutting operations.

3. In an engraving machine, a frame, a carrier mounted upon said frame to freely swing in a vertical plane, a pantograph pivotally mounteldgipon the carrier to swing thereon, cutting ans secured to said pantograph, a model holder mounted upon the carrier and"adapted to swing therewith in said plane during the cutting operations, and guiding means for the pantog'raph adapted to be controlled by the model.

4. In an engraving machine, a frame, a carrier normally free to swing thereon in a vertical plane, a pantograph pivoted to swing upon the carrier, cutting means carried by said pantograph, a work support, a

'model holder upon the carrier adapted to swing therewith, means upon the pantograph adapted to cooperate with a model on said holder to regulate the movement of the cutting means, and adjustable means for limiting the swinging movement of-the carrier to regulate the downward swing of the pantograph.

5. In an engravingmachine, a frame, a work support thereon, a model support pivoted upon the frame above the work support, a holder between said supports adapted to swing in vertical and horizontal planes, a cutter carried by the holder, means for moving the holder in either of said planes, and a guide carried by. the holder having a rounded end for engaging model with a radius greater than that of the a proximately the thickness of the materlal iio be worked between the model and the part to be cut.

6. In an engraving machine, a frame, a carrier mounted to swing in a vertical. plane thereon, a pantograph adapted to swing upon'the carrier, cutting means carried by the pantograph, a work support, and a memthe her adapted to swing with the carrier and forming a guide for directing-the cutting means in a single plane when the pantograph is swung upon the carrier.

7. In an engraving machine, a frame, a pantograph adapted to swing thereon in a vertical plane and also in a direction transverse to said plane, a cutter carried by the pantograph, a support for-the work, and a guide spaced from the work and adapted to direct the cutter in a single plane and permitting it to move vertically while operating in said plane through movement of the pantograph in said vertical plane.

8. In an engraving machine, a frame, a pantograph mounted to swing thereon in a vertical plane and also in a direction transverse to said plane, cutting means carried by the pantograph, a holder above the pantograph, and a detachable device upon the holder arranged to cooperate with the cutting means to cause it to move in a single plane and being adjustable to permit the cutting means to operate in different planes.

9. In an engraving machine, a frame, a carrier pivoted to swing thereon in a vertical plane, a pantograph mounted to swing upon the carrier, cutting means carried by said pantograph, a guide for limiting the movement of the cutting means to a single plane, and a support for the guide adjustable upon the carrier in a direction transverse to the movement of the guide.

10. In an engraving machine, a frame, a pantograph mounted to swing in a vertical plane and also'in a direction transverse to said plane, a cutter movable upon the panmeans for adjusting said guiding means to permit the cutter to operate in different planes.

12. In an engraving machine, a frame, a carrier pivoted to swing about an axis thereon, a pantograph free to swing upon the carrier about an axis transverse to the axis of the carrier, a cutter carried by the pantograph, a support adjustable upon the carrier, a holder adjustable upon the support, and guiding means for the cutter arranged to move in a single plane upon the holder to cause the cutter to move in said plane.

13. In an engraving machine, a frame, a work support, a. carrier pivoted upon the frame to swing about a horizontal axis, a pantograph mounted to swing upon the'carrier' and having a cutter for the work, an adjustable model holder upon the carrier adapted to swing therewith, and a guide for the pantograph mechanism adapted to. be controlled by a model on said holder.

In testimony whereof I hereunto aflix my sighature.

LORENZ KONRAD BRAREN. 

